The present invention relates to an apparatus and method that utilizes a light waveguide to detect the presence, correct installation and/or printing composition characteristics of one or more printing composition containers in a printing device.
One of the main consumable items in printing is the printing composition (e.g., ink or toner) which is typically supplied in replaceable printing composition containers such as cartridges or bags. For proper printing device operation, the containers must be properly installed in the printing device. Failure to do so will cause improper operation and possible damage of the printing device, as well as possible contamination of the printing composition. For example, in a printing device which supports multiple colors of ink, it is desirable to avoid the unwanted mixing of different colors caused by the insertion of a printing composition container of one color into a position reserved for another color. When multiple printing devices are in use which require different ink or toner formulations having different characteristics, it is desirable to avoid the unwanted mixing of one ink or toner formulation into another. This may be caused by insertion of a printing composition container designed for one printing device into another incompatible printing device. It is also desirable to avoid operating a printing device when a required printing composition container is not installed, when a printing composition container is not fully installed, or when a printing composition container is installed in an improper manner.
Current solutions to these problems can be divided into two classes: passive and active. An example of a passive solution to ensure correct printing composition container installation is visual keying. With visual keying, a printing composition container and corresponding receptacle are visually marked with compatible symbols, colors, or words which guide the user to correct installation. With this type of solution, the printing device cannot prevent or detect an incorrect installation. Mechanical keying is an improvement to this type of passive solution. With mechanical keying, incorrect installation is prevented by having mechanical lock-out features on the printing composition container and on the receptacle. These features are designed to interfere or mate with each other thereby preventing printing composition container installation into all but the proper receptacle. A printing composition container may use both visual and mechanical keying.
Problems associated with such passive solutions include inability of detecting and informing the printing device when a required printing composition container has not been installed, has not been fully installed, or has been improperly installed. This limitation gives rise to the use of active solutions whereby means of actively sensing the printing composition container are used.
A common method of active sensing is to make electrical contact between the printing composition container and the printing device. If the electrical connection has not been made, then the printing composition container can be assumed not to be installed, not fully installed, or improperly installed. Electrical identification information incorporated within the printing composition container can also be used to further determine if the container has been installed in a correct receptacle.
A problem with electrical sensing is that of cost and reliability, particularly for containers which are not permanently connected to replaceable printheads. For printing composition containers with replaceable printheads, some electrical connections already exist so the addition of extra signals for container sensing adds a relatively small cost. Containers without printheads attached do not generally require any electrical connections. Therefore, the addition of printing composition container electrical sensing adds noticeable cost. For either configuration, electrical connections for container sensing must be made to each and every container thereby adding cost and increasing the number of connections where contaminates can form and cause reliability problems.
The present invention is directed to alleviation of the above-described problems associated with these currently known solutions. One aspect of the present invention relates to a detection apparatus for use in a printing device that determines whether one or more printing composition containers have been installed in a printing device. The detection apparatus includes at least one container for storing a printing composition, a source that generates a light signal, a detector that detects the light signal from the source when coupled to the source, and a light waveguide that is designed to conduct the light signal from the source to the detector. The detector, in turn, is designed to allow printing by the printing device when the light signal from the source is detected.
The detection apparatus can be designed to allow printing by the printing device only when the container is attached to the device in its proper printing orientation. Additionally or alternatively, the detection apparatus can be designed to allow printing by the printing device only when a container with a printing composition having one or more particular characteristics (e.g., fast drying black ink) is coupled to the device. In such configurations, the light waveguide is designed to fail to conduct light from the source to the detector when the container is not in the printing orientation and/or the container with the one or more particular characteristics is not connected to the device.
Another aspect of the present invention relates to a printing device that includes traditional elements of a printing device (e.g., a print head) plus a circuit that includes a light waveguide. The light waveguide has a conducting position, assumed when all printing composition containers are properly connected to the printing device, in which the printing device is allowed to print. The light waveguide also has a nonconducting position, assumed when any printing composition container is improperly connected to the printing device, in which the printing device is disabled.
Another aspect of the present invention relates to a printing composition container that includes a housing, a body inside the housing that stores a printing composition, and a light waveguide in the housing. The light waveguide is designed to conduct light from a light source to a light detector when the housing is coupled to the printing device in its printing orientation to allow printing by the printing device. The light waveguide is also designed to fail to conduct light from the light source to the light detector when the housing is not in the printing orientation.
The printing composition container may also include a filter (e.g., colored, polarized, or both) that conditions the light signal from the source. In such cases, the detector is configured to detect the conditioned light signal and allow printing only upon detection of the conditioned light signal. The filter may be separate element from the light waveguide or the light waveguide may be formed to act as a filter.
Another aspect of the present invention relates to methods that detect if a printing composition supply is attached to the device in its printing orientation and/or if a printing composition supply having a particular characteristic is attached to the device.
The light waveguide for the various aspects of the present invention may be inside or outside of the containers and housings. The light waveguide may also include two or more separate elements. A first set of these elements can be located in each container or housing and a second set of the elements can be located outside of the containers or housings. These elements can be located at different positions in each container or housing and can also or alternatively be different shapes (e.g., straight, bent or curved). Additionally, these elements may be of different constructions (e.g., light pipes, mirrors, prisms, or other optic elements).
The detection apparatus, printing device, and methods may also include one or more filters, like the filter discussed above in connection with the container. Additionally the above-described containers and bodies for the various aspects of the present invention may be made from bags, and the printing composition in these containers may be ink or toner.
Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.